Field of the Invention
The present invention relates to crystal oscillators and a method of manufacturing the crystal oscillators.
Description Related to the Prior Art
Conventionally, a crystal oscillator that includes a plurality of crystal resonators and is capable of outputting an oscillation signal at a first frequency and an oscillation signal at a second frequency that is different from the first frequency is known. For example, a temperature-compensated crystal oscillator that can output a first oscillation signal to be outputted to an exterior apparatus and a second oscillation signal that is used for a temperature sensor is disclosed in Japanese Unexamined Patent Application Publication No. 2011-135342.
FIG. 12 shows a configuration of a conventional crystal oscillator 100 that outputs signals of two frequencies. As shown in FIG. 12, the conventional crystal oscillator 100 includes a first crystal resonator 101, a first oscillating circuit 102 that oscillates the first crystal resonator 101 at a first frequency, a second crystal resonator 103, and a second oscillating circuit 104 that oscillates the second crystal resonator 103 at a second frequency.
However, since the conventional crystal oscillator 100 includes two crystal resonators, there is a problem that its mounting area is large.
In order to deal with this problem, there is a method that oscillates a crystal resonator at different frequencies at the same time. FIG. 13 shows a configuration of the crystal oscillator 110 that oscillates a crystal resonator at different frequencies at the same time. The crystal oscillator 110 includes a crystal resonator 111, a first oscillating circuit 112 that oscillates the crystal resonator 111 at a first frequency and a second oscillating circuit 113 that oscillates the crystal resonator 111 at a second frequency. However, the crystal oscillator 110 has a problem that each of the oscillating circuits thereof being mutually affected and cannot stably oscillate an output signal.